What are Arithmetic Sequences

Question posted by Sihawukele

An arithmetic sequence is a linear sequence – that means it has a constant difference (d). The pattern is that you add or subtract the same amount from the previous term to get to the next term. For example 2 5 8 11… What we are adding every time is 3: 2 + 3 is 5, 5 + 3 is 8 and so on.

The first term (a) is 2. Now we can create a formula:
Tn(the term value at position n) = a (the first term) + (n (term position) – 1)(d)(the constant difference).

So for clarity : Tn = a + (n – 1)d.

For more information on arithmetic sequences go to the study guide chapters for grade 12 on sequences and Series. Arithmetic series should be in the first section. There are also lots of great exercises you can do to help you practice the concepts you have learnt.